Driving schemes in organic EL display devices include two types, passive matrix and active matrix schemes. Active matrix is the mainstream driving scheme at present, in particular in large display devices.
Ordinarily, the pixels in an active-matrix organic EL display device comprise each one organic EL element that is provided with a switching transistor for transmission of data signal, and with a driving transistor that drives the organic EL element on the basis of a data signal that is transmitted by the switching transistor (for instance, Patent Document 1). Parasitic capacitance arises between these members, which are provided in the pixel, and wiring layers, for instance scanning lines, signal lines and the like. Methods have been proposed in which the display defect known as crosstalk, which derives from this parasitic capacitance, is suppressed by arranging a metallic pattern that constitutes an electric field shield for scanning lines and signal lines (for instance, Patent Document 2).
If the threshold voltage of the driving transistor of each pixel exhibits variability, driving of the driving transistor of each pixel with the same gate voltage results in variability of the current value that is supplied from the driving transistor to the organic EL element. This is one cause of display unevenness. Known methods for solving this problem include, for instance, area gray scale expression or time-division gray scale expression by digital gray scale driving. In the case of analog gray scale driving, methods have been disclosed wherein fluctuation in the threshold voltage of the driving transistor is detected for each pixel, and a so-called compensation circuit is formed that compensates that fluctuation (for instance, Patent Document 3).